Macrophage polarization in THP-1 cell line and primary monocytes: A systematic review

Single-cell impedance spectroscopy of nucleated cells

Single-cell microfluidic impedance spectroscopy is widely used to characterise single cells, but the intrinsic electrical properties are rarely determined owing to the limited number of data points across a wide frequency bandwidth. To address this shortcoming, we have developed a system with an extended frequency range (to 550 MHz) that measures the impedance spectrum of single nucleated cells at high throughput. The system was evaluated using HL60 cells treated with glutaraldehyde or cytochalasin D, and THP-1 cells differentiated into macrophages. The impedance data was fitted to the double-shell model to obtain cell membrane capacitance and cytoplasm conductivity. It is shown that reducing the conductivity of the suspension media significantly enhances the dielectric relaxations of the cell membrane, allowing small differences between control and chemically modified cells to be discriminated.

Immune Modulation with Nanodiscs: Surface Charge Dictates Cellular Interactions and Activation of Macrophages and Dendritic-like Cells

The immunological barrier is among the most significant barriers in vivo. Macrophages and dendritic cells play a crucial role in immune responses, involving phagocytosis, antigen presentation, and triggering adaptive responses. Nanoscale drug-delivery vehicles, such as polymer-encapsulated lipid-bilayer nanodiscs, are of particular interest in the development of new therapeutic approaches, but require well-characterized human in vitro cell models. To this end, the present study differentiated human monocytes into two distinct states, resting macrophages and immature dendritic-like cells (iDCs). These cells served as model systems to assess the efficacy of lipid-bilayer nanodiscs encapsulated by anionic glyco-DIBMA (diisobutylene-maleic acid) or electroneutral sulfo-DIBMA polymers. Nanodisc-cell interaction studies-including cell viability, reactive oxygen species production, cytokine release, particle uptake, and activation marker expression-demonstrated that immune responses depend sensitively on the cell type and polymer and thus on the surface charge of the nanodiscs. Sulfo-DIBMA nanodiscs induced minimal immune cell activation, accompanied by cytokine release and reduced uptake of the nanodiscs by immune cells. In contrast, glyco-DIBMA nanodiscs exhibited increased interactions with cells, elicited pro-inflammatory immune responses, and promoted iDC maturation. This involved co-stimulatory and antigen-presenting molecules, potentially leading to T-cell activation. These findings underscore the potential of glyco-DIBMA nanodiscs to modulate immune responses through receptor-specific interactions, paving the way for immunotherapeutic strategies.

Tumour-associated macrophage infiltration differs in meningioma genotypes, and is important in tumour dynamics

BACKGROUND

Meningiomas are the most common primary intracranial tumours, with clinical behaviours ranging from benign to highly aggressive forms. The World Health Organisation classifies meningiomas into various grades, guiding prognosis and treatment. While surgery is effective for low-grade meningiomas, certain grade 1 tumours, as well as grade 2, 3, and recurrent cases are more aggressive and require new therapeutic approaches. Immunotherapy shows promise, with early-stage clinical trials demonstrating encouraging results. The tumour microenvironment (TME), particularly tumour-associated macrophages (TAMs), plays a pivotal role in tumour progression. TAMs influence tumour growth, metastasis, and immune evasion. However, their role in meningiomas, especially in relation to genomic mutations, remains poorly understood. Understanding how genetic alterations affect the TME is critical for developing targeted immunotherapies.

METHODS

This study employed multiplex immunohistochemistry and bulk RNA sequencing to explore immune infiltration in genetically stratified meningioma tissues and matched three-dimensional (3D) spheroid models. We compared immune cell populations across parental tissues, two-dimensional (2D) monolayer cultures, and 3D spheroid models. In addition, co-culture experiments were conducted, introducing M2-polarised macrophages derived from peripheral blood mononuclear cells to study the interactions between immune cells and tumour cells.

RESULTS

Our findings revealed significant differences in the immune infiltration patterns associated with specific genotypes and methylation classes, especially M2-like TAMs. Notably, the 3D spheroid models more closely replicated the TME observed in parental tissues compared to traditional 2D monolayer cultures, offering a superior platform for immune infiltration studies. Furthermore, co-culture experiments demonstrated that M2-polarised macrophages could effectively infiltrate tumour cells, promote tumour cell proliferation while inhibiting invasion, suggesting IL-6-mediated signalling in tumour progression.

CONCLUSIONS

These findings suggest that 3D co-culture models offer an excellent system for studying the role of immune cells, specifically TAMs, in meningioma progression. By providing a more accurate representation of the TME, these models can help identify novel immunotherapy strategies aimed at modulating the immune response within meningiomas. Ultimately, this approach may improve therapeutic outcomes and quality of life for patients with meningioma by enhancing the effectiveness of existing treatments or by offering new immunotherapeutic options.

TAMs-derived SPP1, regulated by HIF-1α/STAT3 signaling pathway, influences colorectal cancer malignant progression by activation of EMT via integrin αvβ3

Liver metastasis of colorectal cancer (CRC) is characterized by a high recurrence rate after surgery, which may be related to the rerecruitment of residual tumor cells by other factors that promote cancer cell growth in the tumor microenvironment. Tumor-associated macrophages (TAMs), as key immune components, showed high expression of secretory phosphoprotein-1 (SPP1) at the site of liver metastasis in colorectal cancer patients. However, the factors and mechanisms driving the elevated expression of SPP1 in TAMs remain poorly understood, as do the potential effects of SPP1 on colorectal cancer progression. In this study, we investigated the factors that contributed to the high expression of SPP1 in TAMs and its role in promoting the M2 polarization of TAMs. Additionally, we examined the direct impact of SPP1 derived from TAMs on the malignant phenotype of colorectal cancer. The results showed that the two major characteristics of the tumor microenvironment-hypoxia and acidity-synergistically increased the expression of SPP1 in TAMs through the HIF-1α/STAT3 signaling pathway, Moreover, elevated SPP1 protein promoted the M2-like polarization of TAMs by reducing mitochondrial damage and affecting metabolic reprogramming. In addition, TAMs-derived SPP1 could directly influence the malignant progression of colorectal cancer by interacting with αvβ3 integrin through paracrine on the surface of cancer cells. Inhibiting HIF-1α involved in the regulation of SPP1 and blocking the direct action of SPP1 with cancer cells could effectively inhibit liver metastasis of CRC. These findings suggested that blocking the upstream signaling pathway of SPP1 or inhibiting its downstream target could be a promising therapeutic strategy to prevent or reduce liver metastasis recurrence in CRC.

Better models, better treatment? a systematic review of current three dimensional (3D) in vitro models for implant-associated infections

Introduction

Understanding the biology of implant-associated infections is essential in order to provide adequate detection, prevention and therapeutic strategies. Advanced 3D in vitro models offer valuable insights into the complex interactions between cells and bacteria in the presence of implant materials. This review aims to give a comprehensive overview of current 3D in vitro models that mimic implant-associated infections.

Methods

The structured literature search initially identified 258 publications, seven of which fitted the inclusion criteria.

Results

The included 3D models were established either to mimic the in vivo situation (organotypic model) or to investigate future implant materials. In three studies, organotypic models for dental implants were created and one study described an organotypic model containing immune cells. In the remaining three studies, biomaterials for constructing future orthopedic implants were developed and tested. All authors included specific cells and bacteria suitable for the respective implants. The dental implant models used fibroblasts and keratinocytes; the orthopedic implant models used stem cells and fibroblast-like cells; the model containing immune cells incorporated co-cultivation of fibroblasts and THP-1 derived macrophages. For bacterial challenge, most authors used Gram positive bacteria, but three studies employed Gram negative bacterial species. A wide variety of analytical methods of different complexity were applied after co-culture of cells and bacteria and between one and five different methods were used.

Discussion

All models could be employed to provide answers to specific scientific questions regarding implant-associated infections. Nonetheless, this review reveals the limitations of current 3D models for the investigation of implant-associated infections and highlights the opportunities for further development in this scientific field.

TREM-1-Linked Inflammatory Cargo in SARS-CoV-2-Stimulated Macrophage Extracellular Vesicles Drives Cellular Senescence and Impairs Antibacterial Defense

The COVID-19 pandemic, caused by SARS-CoV-2, has significantly affected global health, with severe inflammatory responses leading to tissue damage and persistent symptoms. Macrophage-derived extracellular vesicles (EVs) are involved in the modulation of immune responses, but their involvement in SARS-CoV-2-induced inflammation and senescence remains unclear. Triggering receptors expressed on myeloid cell-1 (TREM-1) are myeloid cell receptors that amplify inflammation, described as a biomarker of the severity and mortality of COVID-19. This study investigated the composition and effects of macrophage-derived EVs stimulated by SARS-CoV-2 (MφV-EVs) on the recipient cell response. Our results, for the first time, show that SARS-CoV-2 stimulation modifies the cargo profile of MφV-EVs, enriching them with TREM-1 and miRNA-155 association, along with MMP-9 and IL-8/CXCL8. These EVs carry senescence-associated secretory phenotype (SASP) components, promote cellular senescence, and compromise antibacterial defenses upon internalization. Our findings provide evidence that MφV-EVs are key drivers of inflammation and immune dysfunction, underscoring their potential as therapeutic targets in COVID-19.

Microneedle delivery of CAR-M-like engineered macrophages alleviates intervertebral disc degeneration through enhanced efferocytosis capacity

Macrophages eliminate apoptotic cells produced daily in the body through efferocytosis. Restricted clearance can cause inflammation-related diseases. In intervertebral discs (IVDs), apoptotic nucleus pulposus cells (NPCs) are difficult to effectively remove, and their accumulation can cause changes in the inflammatory microenvironment, disrupt IVD homeostasis, and lead to IVD degeneration (IDD). Here, we present chimeric antigen receptor-M-like engineered macrophages (CAR-eMs) with enhanced efferocytosis capacity for IDD treatment. Macrophages undergo phenotypic transformation and a reduction in phagocytic ability after phagocyting apoptotic NPCs, but their efferocytosis capacity recovers with upregulated brain-specific angiogenesis inhibitor 1 (BAI1) expression. We develop a CAR-eM system with enhanced BAI1 expression and an IVD circular microneedle (MN) delivery system that utilizes arrays of MNs to deliver CAR-eMs into the deep IVD layers, thereby clearing apoptotic NPCs, ameliorating the inflammatory microenvironment, and repairing damaged IVDs. Our study explores the therapeutic potential of CAR-eM efferocytosis for IDD treatment.

Targeting the poliovirus receptor to activate T cells and induce myeloid-derived suppressor cells to differentiate to pro-inflammatory macrophages via the IFN-γ-p-STAT1-IRF8 axis in cancer therapy

T cell immunoglobulin and ITIM domain (TIGIT) is one of the most important immune checkpoints expressed on lymphocytes, and poliovirus receptor (PVR, also CD155) serves as the most crucial ligand for TIGIT, harboring an important function in cancer cells and influencing the tumor microenvironment (TME). While it's well-established that TIGIT blockade could reverse immunosuppression, the question of whether direct inhibition of PVR yields comparable results remains to be fully elucidated. This study investigated the role of PVR within the TME on the LLC, CT26 and MC38 tumor models and found that direct blockade of PVR on tumor cells could trigger T cell activation, enhance the production of immunostimulatory cytokine IFN-γ, and drive the differentiation of intratumoral myeloid-derived suppressor cells (MDSCs) into pro-inflammatory macrophages through the IFN-γ-p-STAT1-IRF8 axis. Furthermore, this study found that the anti-PVR nanobody monotherapy reduced tumor volume in the CT26 and MC38 tumor models. Combination of anti-PVR nanobody and anti-PD-1 antibody was effective in the LLC, CT26 and MC38 tumor models and had acceptable toxicity. These findings collectively suggest that PVR exhibits considerable promise as a therapeutic target in the development of immunotherapies aimed at augmenting the anti-tumor immune response.

The In Vitro Antioxidant and Immunomodulatory Effects of the Irish Monofloral Ivy and Heather Honey Varieties

Honey has long been valued for its medicinal properties, yet the therapeutic potential of Irish monofloral honey remains largely unexplored. This study investigates the antioxidant and immunomodulatory effects of Irish ivy (Hedera helix) and heather (Calluna vulgaris) honey samples on PMA-differentiated THP-1 macrophages, a well-characterised immune model. Antioxidant capacity was assessed through free radical scavenging assays, DPPH and ORAC, while qPCR analysis examined the key inflammatory markers. Both the heather and ivy honey varieties demonstrated antioxidant activity, with heather honey exhibiting the highest total phenolic content (TPC), and ivy honey stimulating Nrf2 activation. Manuka honey showed the strongest radical scavenging capacity, as reflected in its higher ORAC and DPPH values. These findings suggest that the different honey varieties may exert antioxidant effects through distinct mechanisms. Exposure to honey reduced oxidative stress and upregulated the expression of a key antioxidant transcription regulator (Nrf2) and an associated downstream antioxidant defence enzyme, superoxide dismutase (SOD). Additionally, both the honey types exhibited immunomodulatory effects, upregulating pro-inflammatory cytokines, such as TNF-α and IL-1β, while increasing the expression of the anti-inflammatory cytokine IL-10. These findings suggest potential bioactive properties that warrant further investigation. Given the growing interest in alternative treatments for inflammation-related conditions, further research is warranted to determine whether the observed in vitro effects translate into clinically relevant outcomes. This study expands the current understanding of Irish monofloral honey, reinforcing its potential as a functional bioactive compound with relevance in antioxidant therapies, immune modulation, and wound healing.

Paeonol regulates the DDIT4-mTOR signaling pathway in macrophages to promote diabetic wound healing

BACKGROUND

Diabetic foot ulcers are a common complication in people with diabetes, and patients with severe disease are at risk of amputation. Current studies have found that one of the reasons for the difficulty in healing diabetic foot ulcers is the Abnormal polarization of the M1/M2 phenotype of macrophages, which leads to a prolonged inflammatory period of the wound. The aim of this study was to investigate whether paeonol can promote the polarization of macrophages towards the M2 type and whether M2 type macrophages can regulate the DDIT4-mTOR signaling pathway and slow down the inflammatory response of diabetic foot ulcers.

METHODS

C57BL/6 mice were used to establish an animal model of diabetic foot ulcers and the effect of paeonol on wound healing was investigated. The effects of paeonol on wound healing of foot ulcer in diabetic mice were evaluated using histological staining and immunohistochemistry. The molecular mechanism of refractory healing of foot ulcers was speculated through network pharmacology. The effects of Paeonol on phenotypic polarization of macrophages and the mechanism of inhibiting inflammation were studied by q-PCR, ELISA, immunofluorescence and Western.

RESULTS

Paeonol can effectively promote wound healing in diabetic mice. HE staining showed that paeonol could improve the inflammatory infiltration in the ulcer wound of diabetic mice; Masson trichromatic staining showed that paeonol could increase the increase of muscle fibers and collagen in the wound tissue of diabetic mice; immunofluorescence results showed that paeonol could increase the angiogenesis in the wound tissue of diabetic mice. Network pharmacological analysis showed that the molecular mechanism of paeonol in treating diabetic wound healing may be through DDIT4-mTOR signaling pathway. q-PCR, ELISA, immunofluorescence and Western blot showed that paeonol could reduce the expression of the signature protein CD86 and inflammatory factors in M1 macrophages, and promote the phenotypic polarization of M2 macrophages, which is the mechanism of inhibiting inflammation by activating DDIT4-mTOR signaling pathway.

CONCLUSION

Paeonol can promote the polarization of macrophages towards M2 type, reduce inflammatory response and accelerate wound surface healing through DDIT4-mTOR signaling pathway, providing a new therapeutic strategy for the treatment of diabetic foot ulcers.

Neurotransmitter 5-HT Further Promotes LL-37-Induced Rosacea-like Inflammation Through HTR3A

Rosacea is a chronic inflammatory skin disease and is usually accompanied by extensive macrophage infiltration. There is growing evidence suggesting that neurotransmitter 5-hydroxytryptamine (5-HT) plays a crucial role in inflammatory reactions. However, the interaction between 5-HT and rosacea is still unclear. Here, we hypothesized that the inflammation of rosacea is partly caused by 5-HT, and we investigated the underlying mechanism. In this study, we employed a rosacea model induced by LL-37, which is usually applicated as a rosacea stimulator, to investigate the effects of 5-HT on rosacea in vitro and in vivo. In LL-37-(4 μM)-induced THP-1-derived macrophages, 5-HT (400 μM) further promoted the secretion of inflammatory cytokines and polarized macrophages towards M1 phenotype, which could promote an inflammatory response. Further research revealed that exposure to LL-37 and 5-HT (L5) selectively upregulated HTR3A mRNA expression but not HTR2A or HTR7 and induced colocalization of 5-HT with HTR3A. Notably, application of antagonist tropisetron (TPS) and siRNA of HTR3A suppressed L5-induced inflammation. Meanwhile, 5-HT (25 μg each injection a total of three times) deteriorated skin erythema, stimulated dermal inflammatory cell infiltration, and promoted the secretion of inflammatory cytokines in LL-37 (40 μL and 320 μM each injection a total of four times) induced rosacea-like mice, while these undesirable effects were reversed by using TPS. Our findings revealed that neurotransmitter 5-HT further promoted LL-37-induced rosacea-like inflammation through HTR3A. Our study highlights HTR3A as a promising therapeutic target, which warrants further in-depth investigation into its clinical applicability.

Nell-1 inhibits lipopolysaccharide-activated macrophages into M1 phenotype through the modulation of NF-κB pathway

Nel-like molecule-1 (Nell-1), as a novel osteo-inductive molecule with great potential for clinical applications, has various functions including promoting chondrogenesis, suppressing osteoclastic activity, promoting osteogenesis, suppressing inflammation and promoting vascularization. Its anti-inflammatory potential has been widely studied. However, its anti-inflammatory potential in macrophage and possible underlying molecular mechanisms are poorly understood. Therefore, the present study aims to evaluate the anti-inflammatory potential and the regulation to macrophage polarization of Nell-1 in human myeloid cell line (THP-1) derived macrophages. M1-related markers and M2-related markers were studied in THP-1 derived macrophages. The suppressive potential of Nell-1 on lipopolysaccharide (LPS)-induced translocation of nuclear factor-kappa B (NF-κB) in THP-1 macrophage was studied. Results showed that Nell-1 significantly reduced M1 macrophage-related surface marker cluster of differentiation 86 (CD86) and inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β) and reversed the LPS-induced M1 polarization of macrophages by upregulating the M2-specific markers of vascular endothelial growth factor (VEGF), arginase-1(Arg-1), and cluster of differentiation 206 (CD206) in vitro. In addition, the possible mechanism of the anti-inflammatory effects of Nell-1 is via regulating NF-κB pathway. Hence, Nell-1 is a potential suppressor of inflammation and is involved in the regulation of macrophage polarization. Nell-1 may be a potential candidate for treating inflammatory diseases and promoting tissue regeneration.

CKIP-1 inhibits M2 macrophage polarization to suppress the progression of gastric cancer by inactivating JAK/STAT3 signaling

Gastric cancer (GC) is a frequently occurring malignancy with poor prognosis. Casein kinase 2 interacting protein-1 (CKIP-1) is a PH domain-containing protein implicated in regulating tumorigenesis and macrophage homeostasis. This study aimed to elucidate the role and potential mechanism of CKIP-1 in the progression of GC. CKIP-1 expression in GC tumor and para-carcinoma tissues was detected using RT-qPCR. Then, human monocyte cell line THP-1 was treated with PMA, interleukin (IL)-4 and IL-13 to induce M2-polarized macrophages. CD206, arginase-1 (Arg-1) and transforming growth factorβ1 (TGFβ1) expression in M2-polarized macrophages with or without CKIP-1 overexpression was evaluated. Moreover, GC cell lines (MKN45 and HGC27 cells) were co-cultured with CKIP-1-overexpressed M2-polarized macrophages, and the viability, migration and invasion of GC cells were measured. Additionally, immunoblotting assessed the expression of JAK/STAT3 signaling-related proteins and STAT3 agonist Colivelin was used to treat GC cells to perform the rescue experiments to analyze the changes of malignant phenotypes of GC cells. Results showed that CKIP-1 was downregulated in GC tissues and M2-polarized macrophages. CKIP-1 overexpression inhibited M2 macrophage polarization and decreased TGFβ1 secretion. Besides, elevated CKIP-1 expression in M2-polarized macrophages inhibited the viability, migration and invasion of GC cells. Furthermore, CKIP-1 overexpression inactivated JAK2/STAT3 signaling in GC cells by inhibiting TGFβ1 level. Specifically, Colivelin treatment abrogated the influences of CKIP-1 upregulation on the malignant phenotypes of GC cells. Collectively, CKIP-1 inhibits M2 macrophage polarization to suppress the progression of GC by inactivating JAK/STAT3 signaling pathway.

Influence of macrophages and neutrophilic granulocyte-like cells on crystalline silica-induced toxicity in human lung epithelial cells

In many industrial activities, workers may be exposed by inhalation to particles that are aerosolized, To predict the human health hazard of these materials, we propose to develop a co-culture model (macrophages, granulocytes, and alveolar epithelial cells) designed to be more representative of the inflammatory pulmonary response occurring in vivo. Phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 cells were used as macrophages, All-trans retinoic acid (ATRA)-differentiated HL60 were used as granulocytes and A549 were used as epithelial alveolar type II cells. A crystalline silica sample DQ12 was used as a prototypical particle for its capabilities to induce DNA damage, inflammatory response, and oxidative stress in epithelial cells; its polyvinylpyridine-N-oxide (PVNO)-surface modified counterpart was also used as a negative particulate control. Cells in mono-, bi- or tri-culture were exposed to DQ12 or DQ12-PVNO for 24 h. DQ12 but not DQ12-PVNO induced a significant increase in DNA damage in A549 cells. The presence of differentiated THP-1 reduced the genotoxic effects of this crystalline silica sample. The exposure of A549 to DQ12 but not DQ12-PVNO induced a significant change in interleukin-8 (IL-8) protein levels which was exacerbated when differentiated THP-1, and HL-60, were added. In addition, while no production of TNFα was detected in the A549 monoculture, elevated levels of this cytokine were observed in the co-culture systems. This work shows that a cell culture model that takes into consideration the complexity of the pulmonary inflammatory response might be more dependable to study the toxicological properties of particles than "simple" monoculture models.

In Vitro Infection of Human Macrophages with Porphyromonas gingivalis W83

This study aimed to investigate the innate immune response of human macrophages to Porphyromonas gingivalis W83 using a novel in vitro infection model. The growth kinetics of P. gingivalis W83 were analyzed, revealing an exponential growth phase at 8 h (optical density = 0.70). To establish a reliable macrophage model, the differentiation of THP-1 monocytes into macrophages was optimized using low concentrations of phorbol 12-myristate 13-acetate (PMA). This approach induced enhanced adherence and morphological changes, with full differentiation achieved after 48 h of PMA treatment followed by 24 h of rest. Polarization towards the pro-inflammatory M1 phenotype was successfully induced with interferon-γ (IFN-γ) and lipopolysaccharide (LPS), as confirmed using cytokine profiling. Cytokine analysis using Luminex® technology demonstrated significant increases in interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), and IL-6, indicating the effective activation of macrophages towards a pro-inflammatory phenotype. Building upon this macrophage model, this study investigated the interactions between macrophages and P. gingivalis W83 during its exponential growth phase. After a one-hour infection period, bacterial DNA quantification in supernatants and lysed macrophages revealed minimal levels of internalized or adherent bacteria, supporting the hypothesis that P. gingivalis effectively evades immune detection. These findings emphasize the utility of this model in uncovering the sophisticated immune evasion strategies employed by P. gingivalis, with significant implications for the development of targeted therapeutic interventions.

Luteolin ameliorates periodontitis by modulating mitochondrial dynamics and macrophage polarization via the JAK2/STAT3 pathway

BACKGROUND

Periodontal disease (PD) is a chronic inflammatory condition affecting oral and systemic health. Luteolin (LUT), a natural flavonoid, has shown anti-inflammatory effects, but its therapeutic potential and mechanisms in PD remain unclear.

OBJECTIVE

This study aimed to investigate the effects of LUT on PD, focusing on its impact on mitochondrial dynamics, macrophage polarization, and the JAK2/STAT3 signaling pathway.

METHODS

A combination of network pharmacology analysis and in vivo and in vitro experiments was employed. The efficacy of LUT was evaluated using a ligature-induced rat PD model and LPS-stimulated THP-1-derived macrophages. Key assessments included micro-CT for bone loss, flow cytometry for macrophage polarization, and Western blot for pathway analysis.

RESULTS

LUT significantly reduced alveolar bone loss and enhanced M2 macrophage polarization, as indicated by increased CD206 and Arg1 expression. Additionally, it improved mitochondrial function by reducing ROS and restoring membrane potential, decreasing mitochondrial fission, and promoting mitochondrial fusion. Mechanistically, LUT inhibited JAK2/STAT3 phosphorylation, promoting anti-inflammatory effects.

CONCLUSION

These findings suggest that LUT ameliorates periodontal inflammation and bone loss by modulating mitochondrial dynamics, promoting M2 macrophage polarization, and suppressing the JAK2/STAT3 signaling pathway. This highlights LUT as a promising multitarget candidate for PD treatment.

Macrophage subtypes inhibit breast cancer proliferation in culture

Macrophages are a highly plastic cell type that adopt distinct subtypes and functional states depending on environmental cues. These functional states can vary widely, with distinct macrophages capable of displaying opposing functions. We sought to understand how macrophage subtypes that exist on two ends of a spectrum influence the function of other cells. We used a coculture system with primary human macrophages to probe the effects of macrophage subtypes on breast cancer cell proliferation. Our studies revealed a surprising phenotype in which both macrophage subtypes inhibited cancer cell proliferation compared with cancer cells alone. Of particular interest, using two different proliferation assays with two different breast cancer cell lines, we showed that differentiating macrophages into a "protumor" subtype inhibited breast cancer cell proliferation. These findings are inconsistent with the prevailing interpretation that "protumor" macrophages promote cancer cell proliferation and suggest a re-evaluation of how these interpretations are made.

METTL17-Mediated Inhibition of M1 Macrophage Polarization Alleviates the Progression of Ankylosing Spondylitis

RNA methylation is involved in the pathogenesis of ankylosing spondylitis (AS). This study aimed to investigate the potentials of METTL17 in AS. mRNA expression was detected using RT-qPCR. RNA methylation was detected using MeRIP assay. Protein expression was detected using western blot. Cell proliferation was detected using EdU assay. Macrophage functions was detected using flow cytometry. METTL17 was upregulated after exposure to LPS. However, METTL17 knockdown promoted inflammatory response. Moreover, METTL17 knockdown promoted M1 macrophage polarization. Mechanically, METTL17 regulate RNA methylation. Mechanically, METTL17 promoted the RNA methylation of STAT1, inhibiting the mRNA and protein stability of STAT1. In summary, METTL17 inhibits inflammatory response and M1 macrophage polarization via mediating the RNA methylation of STAT1. Therefore, targeting METTL17/STAT1 may be a promising strategy for AS.

Matrix metalloproteinase-12 by M2 macrophages induced epithelial to mesenchymal transition in chronic rhinosinusitis with nasal polyps

Th2 inflammation and epithelial-mesenchymal transition (EMT) play crucial roles in the pathophysiology of chronic rhinosinusitis with nasal polyps (CRSwNP). This study aimed to investigate the hypothesis that MMP-12, produced by M2 macrophages, induces EMT in nasal epithelial cells, thereby contributing to airway inflammation and remodeling in CRSwNP. The expression levels of MMP-12 were measured by RT-PCR in CRS nasal mucosa and THP-1 cells. mRNA and protein levels of E-cadherin, vimentin, α-SMA, and fibronectin were determined using RT-PCR, western blotting, and immunofluorescence staining in primary nasal epithelial cells and air-liquid interface culture. The expression of MMP-12 was significantly increased in CRSwNP and M2-like THP-1 cells. In co-culture with primary nasal epithelial cells and M2-like THP-1 cells, E-cadherin expression was inhibited, and fibronectin, vimentin, and α-SMA expression were increased. MMP-12 decreased E-cadherin but induced fibronectin, vimentin, and α-SMA mRNA and protein expression in primary nasal epithelial cells and air-liquid interface culture. MMP408, an MMP-12 inhibitor, inhibited EMT-related factors. These findings suggest that MMP-12 expression in M2 macrophages induces EMT in nasal epithelial cells and may contribute to the pathogenesis of CRSwNP.

Extracellular vesicle-packaged miR-4253 secreted by cancer-associated fibroblasts facilitates cell proliferation in gastric cancer by inducing macrophage M2 polarization

Cancer-associated fibroblasts (CAFs) can interact with macrophages in the tumor microenvironment by secreting extracellular vesicles (EVs), thereby affecting tumor progression. However, the mechanisms of CAF-secreted EVs in gastric cancer (GC) remain not well understood. Here, we investigated the effect of CAF-EVs on macrophage polarization in GC and the underlying mechanisms. Macrophage polarization was evaluated using flow cytometry and quantitative real-time polymerase chain reaction. GC cell proliferation was determined using cell counting kit-8, EdU, and colony formation assays. The molecular mechanism was explored using microarray analysis, dual-luciferase reporter assay, and RNA pull-down analysis. The results showed that CAFs secreted EVs that inhibit macrophage M1 polarization and promote M2 polarization. Moreover, miR-4253 expression was increased in CAF-EVs, and inhibition of miR-4253 reversed the macrophage polarization induced by EVs. IL6R was identified as the target of miR-4253. Additionally, macrophages treated with EVs that encapsulated miR-4253 promote GC cell proliferation. In conclusion, CAF-secreted EVs packaging miR-4253 facilitate macrophage polarization from M1 to M2 phenotype by targeting IL6R, thereby accelerating GC cell proliferation. The findings suggest that EV-encapsulated miR-4253 may be a promising therapeutic target of GC.

An investigation of the effect of the protein corona on the cellular uptake of nanoliposomes under flow conditions using quartz crystal microgravimetry with dissipation

When nanoparticle delivery systems are immersed in biological fluids, a complex assembly of proteins forms on their surface, creating a protein corona. The protein corona alters the physicochemical properties, toxicity, biodistribution, cellular uptake, and immune response of the nanoparticles, and consequently, their therapeutic efficacy. Currently, there is a lack of in vitro methods to assess the effects of the protein corona on nanoparticle uptake under dynamic flow and assess their binding kinetics in real-time. Here, we introduce quartz crystal microbalance with dissipation (QCM-D) as an in vitro technique, capable of incorporating dynamic flow, to study the effect of the protein corona on the binding of nanoliposome (NLP) formulations to cell surfaces as a first step in their cellular uptake. The interactions of four NLP formulations (low PEGylated, high PEGylated, negatively charged and positively charged NLPs) with A375 melanoma and THP1 cell lines were assessed by QCM-D, before and after the formation of a protein corona. Through real-time recording of the frequency and dissipation shifts (Δf and ΔD, respectively), the QCM-D results provided strong evidence of the role of the protein corona in the cellular interaction of these NLP formulations, with a variation in their adsorption kinetics depending on their initial composition. NLP's attachment to the cell surface was the lowest for PEGylated NLPs (<5%), while the positively charged NLPs showed the highest cellular attachment (≈100%), regardless of the presence of the protein corona or cell type. The effect of the protein corona was more pronounced for the negatively charged NLPs, where a significant reduction in the NLP attachment was observed. To complement the QCM-D data on the NLP attachment and to determine whether the NLP attachment leads to cellular uptake, confocal microscopy and flow cytometry were used to confirm NLP uptake by A375 and THP1 cells. Proteomic analysis revealed a differential composition of the protein corona on the various NLPs with possible implications for their sequestration and cellular uptake. Collectively, the findings suggest that QCM-D can be an important tool to study the binding of NLP formulations or other nanoparticles with cell membranes under dynamic flow, which very often differs from nanoparticle uptake under static conditions.

Szabo B, Kothalawala RC, Szekelyhidi V, Nagy P, Varga Z, Panyi G, Zakany F. Inhibition of the HV1 voltage-gated proton channel compromises the viability of human polarized macrophages in a polarization- and ceramide-dependent manner

The human voltage-gated proton channel (HV1) provides an efficient proton extrusion pathway from the cytoplasm contributing to the intracellular pH regulation and the oxidative burst. Although its pharmacological inhibition was previously shown to induce cell death in various cell types, no such effects have been examined in polarized macrophages albeit HV1 was suggested to play important roles in these cells. This study highlights that 5-chloro-2-guanidinobenzimidazole (ClGBI), the most widely applied HV1 inhibitor, reduces the viability of human THP-1-derived polarized macrophages at biologically relevant doses with M1 macrophages being the most, and M2 cells the least sensitive to this compound. ClGBI may exert this effect principally by blocking HV1 since the sensitivity of polarized macrophages correlates well with their HV1 expression levels; inhibitors of other macrophage ion channels that may be susceptible for off-target ClGBI effects cause no viability reductions; and Zn2+, another non-specific HV1 blocker, exerts similar effects. As a potential mechanism behind the ClGBI-induced cell death, we identify a complex pH dysregulation involving acidification of the cytoplasm and alkalinization of the lysosomes, which eventually result in membrane ceramide accumulation. Furthermore, ClGBI effects are alleviated by ARC39, a selective acid sphingomyelinase inhibitor supporting the unequivocal significance of ceramide accumulation in the process. Altogether, our results suggest that HV1 inhibition leads to cellular toxicity in polarized macrophages in a polarization-dependent manner, which occurs due to a pH dysregulation and concomitant ceramide overproduction mainly depending on the activity of acid sphingomyelinase. The reduced macrophage viability and plausible concomitant changes in homeostatic M1-M2 balance could contribute to both the therapeutic and potential side effects of HV1 inhibitors that show great promise in the treatment of neuroinflammation and malignant diseases.

Chimeric antigen receptor macrophages targeting c-MET(CAR-M-c-MET) inhibit pancreatic cancer progression and improve cytotoxic chemotherapeutic efficacy

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant tumors. Macrophages are abundant in the tumor microenvironment, making them an attractive target for therapeutic intervention. While current immunotherapies, including immune checkpoint inhibition (ICI) and chimeric antigen receptor T (CAR-T) cells, have shown limited efficacy in pancreatic cancer, a novel approach involving chimeric antigen receptor macrophages (CAR-M) has, although promising, not been explored in pancreatic cancer. In this study, we first investigated the role of CAR-M cells targeting c-MET in pancreatic cancer.

METHODS

The effectiveness and rationality of c-MET as a target for CAR-M in pancreatic cancer were validated through bioinformatic analyses and immunohistochemical staining of samples from pancreatic cancer patients. We utilized flow cytometry and bioluminescence detection methods to demonstrate the specific binding and phagocytic killing effect of CAR-M on pancreatic cancer cells. Additionally, we observed the process of CAR-M engulfing pancreatic cancer cells using confocal microscopy and a long-term fluorescence live cell imaging system. In an in situ tumor model transplanted into NOD/SCID mice, we administered intraperitoneal injections of CAR-M to confirm its inhibitory function on pancreatic cancer. Furthermore, we validated these findings in human monocyte-derived macrophages (hMDM).

RESULTS

Bioinformatics and tumor tissue microarray analyses revealed significantly higher expression levels of c-MET in tumor tissues, compared to the paired peritumoral tissues, and higher c-MET expression correlated with worse patient survival. CAR-M cells were engineered using human monocytic THP-1 cell line and hMDM targeting c-MET (CAR-M-c-MET). The CAR-M-c-MET cells demonstrated highly specific binding to pancreatic cancer cells and exhibited more phagocytosis and killing abilities than the pro-inflammatory polarized control macrophages. In addition, CAR-M-c-MET cells synergized with various cytotoxic chemotherapeutic drugs. In a NOD/SCID murine model, intraperitoneally injected CAR-M-c-MET cells rapidly migrated to tumor tissue and substantially inhibited tumor growth, which did not lead to obvious side effects. Cytokine arrays and mRNA sequencing showed that CAR-M-c-MET produced higher levels of immune activators than control macrophages.

CONCLUSIONS

This study provides compelling evidence for the safety and efficacy of CAR-M therapy in treating pancreatic cancer. The results demonstrate that CAR-M-c-MET significantly suppresses pancreatic cancer progression and enhances the effectiveness of cytotoxic chemotherapy. Remarkably, no discernible side effects occur. Further clinical trials are warranted in human pancreatic cancer patients.

Towards characterization of cell culture conditions for reliable proteomic analysis: in vitro studies on A549, differentiated THP-1, and NR8383 cell lines

Proteomic investigations result in high dimensional datasets, but integration or comparison of different studies is hampered by high variances due to different experimental setups. In addition, cell culture conditions can have a huge impact on the outcome. This study systematically investigates the impact of experimental parameters on the proteomic profiles of commonly used cell lines-A549, differentiated THP-1 macrophage-like cells, and NR8383-for toxicity studies. The work focuses on analyzing the influence at the proteome level of cell culture setup involving different vessels, cell passage numbers, and post-differentiation harvesting time, aiming to improve the reliability of proteomic analyses for hazard assessment. Mass-spectrometry-based proteomics was utilized for accurate protein quantification by means of a label-free approach. Our results showed that significant proteome variations occur when cells are cultivated under different setups. Further analysis of these variations revealed their association to specific cellular pathways related to protein misfolding, oxidative stress, and proteasome activity. Conversely, the influence of cell passage numbers on the proteome is minor, suggesting a reliable range for conducting reproducible biological replicates. Notable, substantial proteome alterations occur over-time post-differentiation of dTHP-1 cells, particularly impacting pathways crucial for macrophage function. This finding is key for the interpretation of experimental results. These results highlight the need for standardized culture conditions in proteomic-based evaluations of treatment effects to ensure reliable results, a prerequisite for achieving regulatory acceptance of proteomics data.

SNHG12 in cancer-associated fibroblast-derived extracellular vesicle induces macrophage-myofibroblast transition

AIMS

To investigate mechanism of lncRNA SNHG12 induced macrophage-myofibroblast transition (MMT) in cancer-associated fibroblasts (CAFs)-derived extracellular vesicles (EVs) in non-small cell lung cancer (NSCLC).

METHOD

CAFs EVs were isolated from human NSCLC tissue and adjacent cancerous tissue (n = 3), and their morphology and particle size were evaluated. Macrophages and MMT cells with different phenotypes were detected, and the binding relationship of lncRNA SNHG12, miR-181a-5p, and Smad3 was verified.

RESULT

LncRNA SNHG12 derived from CAFs-EVs promoted the transformation of M2 macrophages into MMT. In addition, lncRNA-SNHG12 increased the expression of Smad3 which was significantly upregulated in MMT through sponge of miR-181a-5p.

CONCLUSION

LncRNA SNHG12 derived from CAFs-EV induced MMT in NSCLC.

Novel Collagen Analogs with Multicopy Mucin-Type Sequences for Multifunctional Enhancement Properties Using SUMO Fusion Tags

Multifunctional enhanced collagen materials in green biomanufacturing are highly desired yet challenging due to the poor comprehensive performance caused by the adoption of targeting monofunctional peptides. Herein, novel collagen analog design strategy using multicopy tandem of mucin-type sequence (GAPGAPGSQGAPGLQ) derived from human COL1α1 to construct basic building blocks is reported, in which SUMO tag is added to the N-terminal of the protein as a stabilizing core. In particular, novel collagen analogs (named S1506, S1511, S1523, and S1552) with multicopy mucin-type sequences (repeated 6, 11, 23, and 52 times), which were constructed in Escherichia coli, have distinct orientation preferences of functional enhancement (including cell proliferation, differentiation, migration, antioxidant activity, and anti-inflammatory property) compared to COL1α1 in HaCaT and THP-1 cell experiments due to variant three-dimensional structures (the different-length mucin-type polypeptide chains wind around central SUMO tag). Our findings suggest that the innovative protein design and synthesis approaches employed in the construction of these novel S15 proteins have the potential to advance the development of new types of recombinant collagen analogs.

1,25-dihydroxyvitamin D3 augments low-dose PMA-based monocyte-to-macrophage differentiation in THP-1 cells

The human monocytic THP-1 cell line is the most routinely employed in vitro model for studying monocyte-to-macrophage differentiation. Despite the wide use of this model, differentiation protocols using phorbol 12-myristate-13-acetate (PMA) or 1,25-dihydroxyvitamin D3 (1,25D3) vary drastically between studies. Given that differences in differentiation protocols have the potential to impact the characteristics of the macrophages produced, we aimed to assess the efficacy of three different THP-1 differentiation protocols by assessing changes in morphology and gene- and cell surface macrophage marker expression. THP-1 cells were differentiated with either 5 nM PMA, 10 nM 1,25D3, or a combination thereof, followed by a rest period. The results indicated that all three protocols significantly increased the expression of the macrophage markers, CD11b (p < 0.001) and CD14 (p < 0.010). Despite this, THP-1 cells exposed to 1,25D3 alone did not adopt the morphological and expression characteristics associated with macrophages. PMA was required to produce these characteristics, which were found to be more pronounced in the presence of 1,25D3. Both PMA- and PMA with 1,25D3-differentiated THP-1 cells were capable of M1 and M2 macrophage polarization, though the gene expression of polarization-associated markers was most pronounced in PMA with 1,25D3-differentiated THP-1 cells. Moreover, the combination of PMA with 1,25D3 appeared to support the process of commitment to a particular polarization state.

Levilactobacillus brevis IBARAKI-TS3 Isolated From Pickles Promotes Production of Interleukin-10 via Toll-Like Receptor 2 in Human M2 Macrophages

M2 macrophages play an important role in food allergy. Several studies have reported that lactic acid bacteria isolated from pickles exert antiallergic effects. We investigated the effects of several strains of lactic acid bacteria on the immune function of M2 macrophages. M2 macrophages differentiated from THP-1 cell line by interleukin-4 (IL-4) and IL-13 strongly expressed CD163, CD206, and HMOX1 mRNA. Levilactobacillus brevis IBARAKI-TS3 (IBARAKI-TS3) isolated from pickles was identified as a lactic acid bacterium that enhances the expressions of IL-10 and EBI3 mRNA in M2 macrophages. IBARAKI-TS3 induced the expression of genes involved in Toll-like receptor (TLR) signaling, such as IRAK, mitogen-activated protein kinases (MAPKs), and NF-κB mRNA. IBARAKI-TS3-induced IL-10 production was suppressed by anti-TLR2-neutralizing antibodies. Furthermore, the IBARAKI-TS3-induced increase in IL-10 levels was significantly reduced in TLR2-knockdown M2 macrophages compared to M2 macrophages. These results suggest that IBARAKI-TS3 promotes of IL-10 production via TLR2 in M2 macrophages.

PIWI pathway: bridging acute myeloid leukemia stemness and cellular differentiation

PIWI proteins are stem cell-associated RNA-binding proteins crucial for survival of germ stem cells. In cancer, PIWI proteins are overexpressed. Specifically, PIWIL4 is highly expressed in multiple cancers with the highest levels found in acute myeloid leukemia (AML), an aggressive malignancy propagated by a population of leukemia stem cells (LSCs). Bamezai et al. (Blood Journal, blood, 2023, 142, 90-105) demonstrated that PIWIL4 supports AML blasts and LSCs but is not necessary for healthy human hematopoietic progenitor stem cells (HSPCs) function in vivo. PIWIL4 in AML acts by preventing the accumulation of R-loops in key genes for LSCs persistence implicated in: DNA damage, replicative stress, and transcription arrest. We report that PIWIL4 expression significantly decreases in THP-1 monocytes exposed to a differentiating agent, suggesting a potential role for PIWIL4 in maintaining the undifferentiated state of myeloid cells. PIWIL4 overexpression could lead to the emergence of LSCs, driving leukemia propagation and maintenance. Our findings correlate with the persistent overexpression of PIWIL4 in myeloid cancers as reported by Bamezai et al., and suggest that PIWIL4 may be involved in myeloid cell differentiation. In this perspective, we highlight recent findings on the implication of PIWI pathway in maintaining AML stemness. Additionally, we propose further investigation on the role of PIWI pathway in oncogenesis and cellular differentiation as a strategy to identify biomarkers and therapeutic targets for AML.

Imbalance polarization of M1/M2 macrophages in miscarried uterus

BACKGROUND

Lipopolysaccharides (LPS) is well known to manifest a miscarriage-inducing effector during early pregnancy and activate macrophage to induce M1 macrophage polarization. However, the role of macrophage polarization in LPS-related miscarriage-inducing effect is not apparent.

METHODS

In this work, gene expression changes and the percentage of M1/M2 macrophages and monocytes in LPS-induced miscarried uterus were firstly analyzed by RNA sequencing (RNA-seq) and Flow Cytometry. To explore the origin that contributes to M1/M2 macrophage differentiation, the expression of monocyte chemotactic protein (MCP-1), CCL3, and CCL4, chemokines related to monocyte/macrophage migration, was tested by quantitative real time PCR (qRT-PCR).

RESULTS

We found that percentage of M1 macrophages rose, while the percentage of M2 macrophages declined down in the injected mice uterus. Meanwhile, the percentage of M1 and M2 macrophages showed no significant difference in the spleens of LPS injected mice compared to PBS injected control mice. Expression of Mcp-1, Ccl3, and Ccl4 and numbers of monocytes were remarkably up-regulated in LPS-induced miscarried mice uterus.

CONCLUSION

These results indicated that polarization and proportion changes of macrophage in the uterus may contribute to miscarriage. Our work provides new evidence correlating the aberrant regulation of M1/M2 macrophage polarization with deleterious miscarriage-inducing effects. This will help us understand the roles of critical immune cell differentiation in maintaining normal pregnancy.

Chlorinated Anthracenes Induced Pulmonary Immunotoxicity in 3D Coculture Spheroids Simulating the Lung Microenvironment

Chlorinated anthracenes (Cl-Ants), persistent organic pollutants, are widely detected in the environment, posing potential lung toxicity risks due to frequent respiratory exposure. However, direct evidence and a comprehensive understanding of their toxicity mechanisms are lacking. Building on our prior findings of Cl-Ants' immunotoxic risks, this study developed a three-dimensional coculture spheroid model mimicking the lung's immune microenvironment. The objective is to explore the pulmonary immunotoxicity and comprehend its mechanisms, taking into account the heightened immune reactivity and frequent lung exposure of Cl-Ants. The results demonstrated that Cl-Ants exposure led to reduced spheroid size, increased macrophage migration outward, lowered cell viability, elevated 8-OHdG levels, disturbed anti-infection balance, and altered cytokine production. Specifically, the chlorine substituent number correlates with the extent of disruption of spheroid indicators caused by Cl-Ants, with stronger immunotoxic effects observed in dichlorinated Ant compared to those in monochlorinated Ant. Furthermore, we identified critical regulatory genes associated with cell viability (ALDOC and ALDOA), bacterial response (TLR5 and MAP2K6), and GM-CSF production (CEBPB). Overall, this study offers initial in vitro evidence of low-dose Cl-PAHs' pulmonary immunotoxicity, advancing the understanding of Cl-Ants' structure-related toxicity and improving external toxicity assessment methods for environmental pollutants, which holds significance for future monitoring and evaluation.

Discovery and functional characterization of LncRNAs associated with inflammation and macrophage activation

Long noncoding RNAs (lncRNA) are emerging players in regulation of gene expression and cell signaling and their dysregulation has been implicated in a multitude of human diseases. Recent studies from our laboratory revealed that lncRNAs play critical roles in cytokine regulation, inflammation, and metabolism. We demonstrated that lncRNA HOTAIR, which is a well-known regulator of gene silencing, plays critical roles in modulation of cytokines and proinflammatory genes, and glucose metabolism in macrophages during inflammation. In addition, we recently discovered a series of novel lncRNAs that are closely associated with inflammation and macrophage activation. We termed these as long-noncoding inflammation associated RNAs (LinfRNAs). We are currently engaged in the functional characterization of these hLinfRNAs (human LinfRNAs) with a focus on their roles in inflammation, and we are investigating their potential implications in chronic inflammatory human diseases. Here, we have summarized experimental methods that have been utilized for the discovery and functional characterization of lncRNAs in inflammation and macrophage activation.

Anti-inflammatory actions of aspirin-triggered resolvin D1 (AT-RvD1) in bronchial epithelial cells stimulated by cigarette smoke extract

Smoking causes several diseases such as chronic obstructive pulmonary disease (COPD). Aspirin-triggered-resolvin D1 (AT-RvD1) is a lipid mediator produced during the resolution of inflammation and demonstrates anti-inflammatory and pro-resolution effects in several inflammatory experimental models including in the airways. Here we evaluated the role of AT-RvD1 (100 nM) in bronchial epithelial cells (BEAS-2B) stimulated by cigarette smoke extract (CSE; 1%; 1 cigarette) for 24 h. CSE induced the productions of IL-1β, TNF-α, IL-10, IL-4 and IFN-γ as well as the activations of NF-κB and STAT3 and the expression of ALX/FPR2 receptor. AT-RvD1 reduced the IL-1β and TNF-α production and increased the production of IFN-γ. These effects were reversed BOC2, an antagonist of ALX/FPR2 receptor for AT-RvD1. The production of IL-4 and IL-10 were not altered by AT-RvD1. In addition, AT-RvD1 reduced the phosphorylation of NF-κB and STAT3 when compared to CSE-stimulated BEAS-2B cells. No alteration of ALX/FPR2 expression was observed by AT-RvD1 when compared to CSE group. In the human monocytic leukemia cell line, the relative number of copies of IL-1β and IL-4 was significantly higher in CSE + AT-RvD1 group compared CSE group, however, the expression of M1 cytokine was more pronounced than M2 profile. AT-RvD1 could be an important target for the reduction of inflammation in the airways associated with smoking.

Macrophage subtypes inhibit breast cancer proliferation in culture

Macrophages are a highly plastic cell type that adopt distinct subtypes and functional states depending on environmental cues. These functional states can vary wildly, with distinct macrophages capable of displaying opposing functions. We sought to understand how macrophage subtypes that exist on two ends of a spectrum influence the function of other cells. We used a co-culture system with primary human macrophages to probe the effects of macrophage subtypes on breast cancer cell proliferation. Our studies revealed a surprising phenotype in which both macrophage subtypes inhibited cancer cell proliferation compared to cancer cells alone. Of particular interest, using two different proliferation assays with two different breast cancer cell lines, we showed that differentiating macrophages into a "pro-tumor" subtype inhibited breast cancer cell proliferation. These findings are inconsistent with the prevailing interpretation that "pro-tumor" macrophages promote cancer cell proliferation and suggest a re-evaluation of how these interpretations are made.

Immunomodulatory activity of argentatins A and B isolated from guayule

Argentatins are secondary metabolites synthesized by guayule (Parthenium argentatum A. Gray) with numerous potential medical applications. In addition to inhibiting insect growth, they are endowed with several pharmacological properties including antimicrobial and antitumorigenic activity. However, their potential as immunomodulators remains unexplored. The aim of the present study was to investigate whether argentatins can modulate the function of the immune system. Human mesenchymal stem cells were treated with argentatins and the production of several anti- and proinflammatory cytokines was evaluated. The effect of argentatins on the polarization of CD4+ T-lymphocytes and macrophages was also assessed. Results demonstrated that argentatins can modulate the production of proinflammatory cytokines and the polarization of cellular phenotypes, including Th2 lymphocytes and M1 macrophages. These findings suggest that argentatins are promising therapeutic agents in autoimmune or allergic diseases, and open new perspectives for the investigation of argentatins in immune response and in the development of more targeted and effective immunomodulatory therapies.

Unmasking the dynamics of Mycoplasma gallisepticum: deciphering HD11 macrophage polarization for innovative infection control strategies

Mycoplasma gallisepticum (MG) is a highly contagious avian respiratory pathogen characterized by rapid spread, widespread distribution, and long-term persistence of infection. Previous studies have shown that chicken macrophage HD11 cells play a critical role in the replication and immunomodulation of MG. Macrophages are multifunctional immunomodulatory cells that polarize into different functions and morphologies in response to exogenous stimuli. However, the effect of MG infection on HD11 polarization is not well understood. In this study, we observed a time-dependent increase in both the expression of the MG-related virulence protein pMGA1.2 and the copy number of MG upon MG infection. Polarization studies revealed an upregulation of M1-type marker genes in MG-infected HD11 cells, suggesting that MG mainly induces HD11 macrophages towards M1-type polarization. Furthermore, MG activated the inflammatory vesicle NLRP3 signaling pathway, and NLRP3 inhibitors affected the expression of M1 and M2 marker genes, indicating the crucial regulatory role of the NLRP3 signaling pathway in MG-induced polarization of HD11 macrophages. Our findings reveal a novel mechanism of MG infection, namely the polarization of MG-infected HD11 macrophages. This discovery suggests that altering the macrophage phenotype to inhibit MG infection may be an effective control strategy. These findings provide new perspectives on the pathogenic mechanism and control measures of MG.

Macrophage Polarization Dynamics in Biomaterials: Implications for in Vitro Wound Healing

The interaction between biomaterials and the immune system plays a pivotal role in determining the success or failure of implantable devices. Macrophages, as key orchestrators of immune responses, exhibit diverse reactions that influence tissue integration or lead to implant failure. This study focuses on unraveling the intricate relationship between macrophage phenotypes and biomaterials, specifically hydrogels, by employing THP-1 cells as a model. Through a comprehensive investigation using polysaccharide, polymer, and protein-based hydrogels, our research sheds light on how the properties of hydrogels influence macrophage polarization. Phenotypic observations, biochemical assays, surface marker expression, and gene expression profiles collectively demonstrate the differential macrophage polarization abilities of polysaccharide-, polymer-, and protein-based hydrogels. Moreover, our indirect coculture studies reveal that hydrogels fostering M2 polarization exhibit exceptional wound-healing capabilities. These findings highlight the crucial role of the hydrogel microenvironment in adjusting macrophage polarization, offering a fresh avenue for refining biomaterials to bolster advantageous immune responses and improve tissue integration. This research contributes valuable insights for designing biomaterials with tailored properties that can guide macrophage behavior, ultimately improving the overall success of implantable devices.

Macrophage polarization in adenomyosis: A review

Adenomyosis (AM) is a common gynecological disorder characterized by the presence of endometrial glands and stroma within the uterine myometrium. It is associated with abnormal uterine bleeding (AUB), dysmenorrhea, and infertility. Although several mechanisms have been proposed to elucidate AM, the exact cause and development of the condition remain unclear. Recent studies have highlighted the significance of macrophage polarization in the microenvironment, which plays a crucial role in AM initiation and progression. However, a comprehensive review regarding the role and regulatory mechanism of macrophage polarization in AM is currently lacking. Therefore, this review aims to summarize the phenotype and function of macrophage polarization and the phenomenon of the polarization of adenomyosis-associated macrophages (AAMs). It also elaborates on the role and regulatory mechanism of AAM polarization in invasion/migration, fibrosis, angiogenesis, dysmenorrhea, and infertility. Furthermore, this review explores the underlying molecular mechanisms of AAM polarization and suggests future research directions. In conclusion, this review provides a new perspective on understanding the pathogenesis of AM and provides a theoretical foundation for developing targeted drugs through the regulation of AAM polarization.

Mineralized collagen scaffolds for regenerative engineering applications

Collagen is a primary constituent of the tissue extracellular matrix. As a result, collagen has been a common component of tissue engineering biomaterials, including those to promote bone regeneration or to investigate cell-material interactions in the context of bone homeostasis or disease. This review summarizes key considerations regarding current state-of-the-art design and use of collagen biomaterials for these applications. We also describe strategic opportunities for collagen biomaterials to address a new era of challenges, including immunomodulation and appropriate consideration of sex and other patient characteristics in biomaterial design.

Molecular mechanisms of macrophage immunomodulation mediated by Areca inflorescence polysaccharides based on RNA-seq analysis

The elucidation of the immunomodulatory molecular mechanisms of polysaccharides has contributed to their further development and application. In this study, the effect of Areca inflorescence polysaccharide (AFP2a) on macrophage activation was confirmed and the detailed mechanisms were investigated based on a comprehensive transcriptional study and specific inhibitors. The results showed that AFP2a induced macrophage activation (M1 polarization), promoting macrophage proliferation, reactive oxygen species production, nitric oxide and cytokine release, and costimulatory molecule expression. RNA-seq analysis identified 5919 differentially expressed genes (DEGs). For DEGs, GO, KEGG, and Reactome enrichment analyses and PPI networks were conducted, elucidating that AFP2a activated macrophages mainly by triggering the Toll-like receptor cascade and corresponding adapter proteins (TIRAP and TRIF), thereby resulting in downstream NF-κB, TNF, and JAK-STAT signaling pathway expression. The inhibition assay revealed that TLR4 and TLR2 were essential for the recognition of AFP2a. This work provides an in-depth understanding of the immunoregulatory mechanism of AFP2a while offering a molecular basis for AFP2a to serve as a potential natural immunomodulator.

In vitro inflammation and toxicity assessment of pre- and post-incinerated organomodified nanoclays to macrophages using high-throughput screening approaches

BACKGROUND

Organomodified nanoclays (ONC), two-dimensional montmorillonite with organic coatings, are increasingly used to improve nanocomposite properties. However, little is known about pulmonary health risks along the nanoclay life cycle even with increased evidence of airborne particulate exposures in occupational environments. Recently, oropharyngeal aspiration exposure to pre- and post-incinerated ONC in mice caused low grade, persistent lung inflammation with a pro-fibrotic signaling response with unknown mode(s) of action. We hypothesized that the organic coating presence and incineration status of nanoclays determine the inflammatory cytokine secretary profile and cytotoxic response of macrophages. To test this hypothesis differentiated human macrophages (THP-1) were acutely exposed (0-20 µg/cm2) to pristine, uncoated nanoclay (CloisNa), an ONC (Clois30B), their incinerated byproducts (I-CloisNa and I-Clois30B), and crystalline silica (CS) followed by cytotoxicity and inflammatory endpoints. Macrophages were co-exposed to lipopolysaccharide (LPS) or LPS-free medium to assess the role of priming the NF-κB pathway in macrophage response to nanoclay treatment. Data were compared to inflammatory responses in male C57Bl/6J mice following 30 and 300 µg/mouse aspiration exposure to the same particles.

RESULTS

In LPS-free media, CloisNa exposure caused mitochondrial depolarization while Clois30B exposure caused reduced macrophage viability, greater cytotoxicity, and significant damage-associated molecular patterns (IL-1α and ATP) release compared to CloisNa and unexposed controls. LPS priming with low CloisNa doses caused elevated cathepsin B/Caspage-1/IL-1β release while higher doses resulted in apoptosis. Clois30B exposure caused dose-dependent THP-1 cell pyroptosis evidenced by Cathepsin B and IL-1β release and Gasdermin D cleavage. Incineration ablated the cytotoxic and inflammatory effects of Clois30B while I-CloisNa still retained some mild inflammatory potential. Comparative analyses suggested that in vitro macrophage cell viability, inflammasome endpoints, and pro-inflammatory cytokine profiles significantly correlated to mouse bronchioalveolar lavage inflammation metrics including inflammatory cell recruitment.

CONCLUSIONS

Presence of organic coating and incineration status influenced inflammatory and cytotoxic responses following exposure to human macrophages. Clois30B, with a quaternary ammonium tallow coating, induced a robust cell membrane damage and pyroptosis effect which was eliminated after incineration. Conversely, incinerated nanoclay exposure primarily caused elevated inflammatory cytokine release from THP-1 cells. Collectively, pre-incinerated nanoclay displayed interaction with macrophage membrane components (molecular initiating event), increased pro-inflammatory mediators, and increased inflammatory cell recruitment (two key events) in the lung fibrosis adverse outcome pathway.

Endogenous Zinc-Ion-Triggered In Situ Gelation Enables Zn Capture to Reprogram Benign Hyperplastic Prostate Microenvironment and Shrink Prostate

Benign prostatic hyperplasia (BPH) as the leading cause of urination disorder is still a refractory disease, and there have no satisfied drugs or treatment protocols yet. With identifying excessive Zn2+ , inflammation, and oxidative stress as the etiology of aberrant hyperplasia, an injectable sodium alginate (SA) and glycyrrhizic acid (GA)-interconnected hydrogels (SAGA) featuring Zn2+ -triggered in situ gelation are developed to load lonidamine for reprogramming prostate microenvironment and treating BPH. Herein, SAGA hydrogels can crosslink with Zn2+ in BPH via coordination chelation and switch free Zn2+ to bound ones, consequently alleviating Zn2+ -arisen inflammation and glycolysis. Beyond capturing Zn2+ , GA with intrinsic immunoregulatory property can also alleviate local inflammation and scavenge reactive oxygen species (ROS). Intriguingly, Zn2+ chelation-bridged interconnection in SAGA enhances its mechanical property and regulates the degradation rate to enable continuous lonidamine release, favoring hyperplastic acini apoptosis and further inhibiting glycolysis. These multiple actions cooperatively reprogram BPH microenvironment to alleviate characteristic symptoms of BPH and shrink prostate. RNA sequencing reveals that chemotaxis, glycolysis, and tumor necrosis factor (TNF) inflammation-related pathways associated with M1-like phenotype polarization are discerned as the action rationales of such endogenous Zn2+ -triggered in situ hydrogels, providing a candidate avenue to treat BPH.

Establishment of a Human Immunocompetent 3D Tissue Model to Enable the Long-Term Examination of Biofilm-Tissue Interactions

Different studies suggest an impact of biofilms on carcinogenic lesion formation in varying human tissues. However, the mechanisms of cancer formation are difficult to examine in vivo as well as in vitro. Cell culture approaches, in most cases, are unable to keep a bacterial steady state without any overgrowth. In our approach, we aimed to develop an immunocompetent 3D tissue model which can mitigate bacterial outgrowth. We established a three-dimensional (3D) co-culture of human primary fibroblasts with pre-differentiated THP-1-derived macrophages on an SIS-muc scaffold which was derived by decellularisation of a porcine intestine. After establishment, we exposed the tissue models to define the biofilms of the Pseudomonas spec. and Staphylococcus spec. cultivated on implant mesh material. After 3 days of incubation, the cell culture medium in models with M0 and M2 pre-differentiated macrophages presented a noticeable turbidity, while models with M1 macrophages presented no noticeable bacterial growth. These results were validated by optical density measurements and a streak test. Immunohistology and immunofluorescent staining of the tissue presented a positive impact of the M1 macrophages on the structural integrity of the tissue model. Furthermore, multiplex ELISA highlighted the increased release of inflammatory cytokines for all the three model types, suggesting the immunocompetence of the developed model. Overall, in this proof-of-principle study, we were able to mitigate bacterial overgrowth and prepared a first step for the development of more complex 3D tissue models to understand the impact of biofilms on carcinogenic lesion formation.

Manganese@Albumin Nanocomplex and Its Assembled Nanowire Activate TLR4-Dependent Signaling Cascades of Macrophages

The immunomodulatory effect of divalent manganese cations (Mn2+ ), such as activation of the cGAS-STING pathway or NLRP3 inflammasomes, positions them as adjuvants for cancer immunotherapy. In this study, it is found that trace Mn2+ ions, bound to bovine serum albumin (BSA) to form Mn@BSA nanocomplexes, stimulate pro-inflammatory responses in human- or murine-derived macrophages through TLR4-mediated signaling cascades. Building on this, the assembly of Mn@BSA nanocomplexes to obtain nanowire structures enables stronger and longer-lasting immunostimulation of macrophages by regulating phagocytosis. Furthermore, Mn@BSA nanocomplexes and their nanowires efficiently activate peritoneal macrophages, reprogramme tumor-associated macrophages, and inhibit the growth of melanoma tumors in vivo. They also show better biosafety for potential clinical applications compared to typical TLR4 agonists such as lipopolysaccharides. Accordingly, the findings provide insights into the mechanism of metalloalbumin complexes as potential TLR agonists that activate macrophage polarization and highlight the importance of their nanostructures in regulating macrophage-mediated innate immunity.

Transcriptomic Analysis of THP-1 Cells Exposed by Monosodium Urate Reveals Key Genes Involved in Gout

BACKGROUND

Gout is a common inflammatory arthritis, which is mainly caused by the deposition of monosodium urate (MSU) in tissues. Transcriptomics was used to explore the pathogenesis and treatment of gout in our work.

OBJECTIVE

The objective of the study was to analyze and validate potential therapeutic targets and biomarkers in THP-1 cells that were exposed to MSU.

METHODS

THP-1 cells were exposed to MSU. The inflammatory effect was characterized, and RNA-Seq analysis was then carried out. The differential genes obtained by RNA-Seq were analyzed with gene expression omnibus (GEO) series 160170 (GSE160170) gout-related clinical samples in the GEO database and gout-related genes in the GeneCards database. From the three analysis approaches, the genes with significant differences were verified by the differential genes' transcription levels. The interaction relationship of long non-coding RNA (lncRNA) was proposed by ceRNA network analysis.

RESULTS

MSU significantly promoted the release of IL-1β and IL-18 in THP-1 cells, which aggravated their inflammatory effect. Through RNA-Seq, 698 differential genes were obtained, including 606 differential mRNA and 92 differential `LncRNA. Cross-analysis of the RNA-Seq differential genes, the GSE160170 differential genes, and the gout-related genes in GeneCards revealed a total of 17 genes coexisting in the tripartite data. Furthermore, seven differential genes-C-X-C motif chemokine ligand 8 (CXCL8), C-X-C motif chemokine ligand 2 (CXCL2), tumor necrosis factor (TNF), C-C motif chemokine ligand 3 (CCL3), suppressor of cytokine signaling 3 (SOCS3), oncostatin M (OSM), and MIR22 host gene (MIR22HG)-were verified as key genes that analyzed the weight of genes in pathways, the enrichment of inflammationrelated pathways, and protein-protein interaction (PPI) nodes combined with the expression of genes in RNA-Seq and GSE160170. It is suggested that MIR22HG may regulate OSM and SOCS3 through microRNA 4271 (miR-4271), OSM, and SOCS3m; CCL3 through microRNA 149-3p (miR-149-3p); and CXCL2 through microRNA 4652-3p (miR-4652-3p).

CONCLUSION

The potential of CXCL8, CXCL2, TNF, CCL3, SOCS3, and OSM as gout biomarkers and MIR22HG as a therapeutic target for gout are proposed, which provide new insights into the mechanisms of gout biomarkers and therapeutic methods.

Small Molecule Decoy of Amyloid-β Aggregation Blocks Activation of Microglia-Like Cells

Background

Aggregated forms of the amyloid-β (Aβ) peptides which form protofibrils and fibrils in the brain are signatures of Alzheimer's disease (AD). Aggregates are also recognized by microglia, which in early phases may be protective and in later phases contribute to the pathology. We have identified several small molecules, decoys which interfere with Aβ oligomerization and induce other aggregation trajectories leading to aggregated macrostructures which are non-toxic.

Objective

This study investigates whether the small-molecule decoys affect microglial activation in terms of cytokine secretion and phagocytosis of Aβ peptide.

Methods

The effects of the decoys (NSC 69318, NSC 100873, NSC 16224) were analyzed in a model of human THP-1 monocytes differentiated to microglia-like cells. The cells were activated by Aβ40 and Aβ42 peptides, respectively, and after treatment with each decoy the secreted levels of pro-inflammatory cytokines and the Aβ phagocytosis were analyzed.

Results

NSC16224, which generates a double-stranded aggregate of thin protofibrils, was found to block Aβ40- and Aβ42-induced increase in microglial secretion of pro-inflammatory cytokines. NSC 69318, selective for neurotoxicity of Aβ42, and NSC 100873 did not significantly reduce the microglial activation in terms of cytokine secretion. The uptake of Aβ42 was not affected by anyone of the decoys.

Conclusions

Our findings open the possibility that the molecular decoys of Aβ aggregation may block microglial activation by Aβ40 and Aβ42 in addition to blocking neurotoxicity as shown previously.

Dendrobium officinale polysaccharide Converts M2 into M1 Subtype Macrophage Polarization via the STAT6/PPAR-r and JAGGED1/NOTCH1 Signaling Pathways to Inhibit Gastric Cancer

Dendrobium officinale polysaccharide (DOP) has shown various biological activities. However, the ability of DOP to participate in immune regulation during anti-gastric cancer treatment has remained unclear. In this study, the in vitro results showed that DOP has the potential to polarize THP-1 macrophages from the M2 to the M1 phenotype, downregulate the STAT6/PPAR-r signaling pathway and the protein expression of their down-targeted ARG1 and TGM2, and further decrease the main protein and mRNA expression in the JAGGED1/NOTCH1 signaling pathway. DOP suppressed the migration of gastric cancer cells by decreasing the protein expression of N-cadherin and Vimentin and increasing E-cadherin. In addition, CM-DOP promoted the apoptosis of gastric cancer cells by upregulating Caspase-3 and increasing the ratio of Bax/Bcl-2. In vivo, DOP effectively inhibited the growth of tumors and the expression of Ki-67. In summary, these findings demonstrated that DOP converted the polarization of M2 subtype macrophages into M1 subtypes via the STAT6/PPAR-r and JAGGED1/NOTCH1 signaling pathways in order to reduce apoptosis and prevent migration, thus indicating the potential of DOP as an adjuvant tumor therapy in preclinical and clinical trials.

Four new triterpene saponins from Cephalaria speciosa and their potent cytotoxic and immunomodulatory activities

Four new triterpene saponins, namely speciosides A-D (1-4) along with six known saponins were isolated from the n-butanol extract of Cephalaria speciosa. In addition to these, three new prosapogenins (2a-4a) were obtained after alkaline hydrolysis. Elucidation of the structures of the isolated compounds was carried out by 1D, 2D NMR, HR-ESI/MS and GC-MS analyses. Cytotoxic activity was investigated on A549, CCD34-Lu, MDA-MB-231, PC-3, U-87MG, HeLa, HepG-2 cells by MTT method. Additionally, the immunomodulatory effect of compounds was evaluated for macrophage polarization with/without inactivated IBV D274 antigen treatment on THP-1 cells originated macrophage cells in terms of M1 or M2. According to the cytotoxicity results, compound 1 and prosapogenin 2a exhibit significant cytotoxicity than doxorubicin by comparison. The results demonstrated that saponin molecules treated THP-1 originated macrophages were induced M1 and/or M2 polarization. Additionally, macrophage cells treated with/without IBV D274 antigen contained saponin compounds were triggered significantly M2 polarization relative to M1. Notably, monodesmosidic saponins (1 and 2a-4a) in comparison with bisdesmosidic ones (2-4) demonstrated the most effect on M2 polarization. In conclusion, the results showed that all the isolated new saponins and their prosapogenins have immunomodulatory potential on macrophage cells increasing immune response without significant cytotoxic effect on THP-1 originated macrophages.

OTUB1's role in promoting OSCC development by stabilizing RACK1 involves cell proliferation, migration, invasion, and tumor-associated macrophage M1 polarization

Ovarian tumor domain, ubiquitin aldehyde binding 1 (OTUB1), a deubiquitinating enzyme known to regulate the stability of downstream proteins, has been reported to regulate various cancers tumorigenesis, yet its direct effects on oral squamous cell carcinoma (OSCC) progression are unclear. Bioinformatics analysis was performed to screen for genes of interest, and in vitro and in vivo studies were carried out to investigate the function and mechanism of OTUB1 in OSCC. We found that OTUB1 was abnormally elevated in OSCC tissues and positively associated with the pathological stage and tumor stage. Knockdown of OTUB1 impaired the malignance of OSCC cells - suppressed cell proliferation, invasion, migration, and xenografted tumor growth. OTUB1 silencing also drove tumor-associated macrophage M1 polarization but suppressed M2 polarization, and the induction of M1 polarization inhibited the survival of OSCC cells. However, OTUB1 overexpression exerted the opposite effects. Furthermore, the protein network that interacted with the OTUB1 protein was constructed based on the GeneMANIA website. Receptor for activated C kinase 1 (RACK1), a facilitator of OSCC progression, was identified as a potential target of the OTUB1 protein. We revealed that OTUB1 positively regulated RACK1 expression and inhibited RACK1 ubiquitination. Additionally, RACK1 upregulation reversed the effects of OTUB1 knockdown on OSCC progression. Overall, we demonstrated that OTUB1 might regulate OSCC progression by maintaining the stability of the RACK1 protein. These findings highlight the potential roles of the OTUB1/RACK1 axis as a potential therapeutic target in OSCC.